That divot appears to have been made while installing the wheel bearing. I can't imagine any reason you couldn't use a high speed drill motor or a Dremel tool and a small grinding wheel to smooth it out. I've also had some success with getting a seal to start in the bore by grinding a slight chamfer onto the leading edge of the seal. It won't cause any leakage because there's plenty more straight area to make a leakproof fit on the outside as the seal slides into place.
Thanks, Jerry! I wound up using a small rattail file to smooth out the ridge in the sealing surface caused by the divot. I then took some 400 grit followed by 1000 grit sandpaper to smooth it out. I got the new seal in, but the block of wood I was using to seat the seal got a little off center and I bent the inner edge of the new seal. darn (and several other colorful words). I've ordered a new seal along with an installation tool and hope to have it all buttoned up by Tuesday or Wednesday. Here's hoping I run into no more unexpected issues!